A&P- Chapter 5: The Integumentary System
Describe the subcutaneous layer.
The subcutaneous layer is a layer of areolar tissue containing many adipose (fat) cells, which lies below the dermis. It is not considered a aprt of the integument, but it is important in stabilizing the position of the skin in relation to underlying tissue.
List the two terms for the tissue that connects the dermis to underlying tissues.
The tissue that connects the dermis to underlining tissues is the subcutaneous layer or hypodermis.
Some criminals sand their fingertips to avoid leaving recognizable fingerprints. Would this practice permanently remove fingerprints? Why or why not?
Sanding the tips of the fingers will not permanetely remove fingertips. The ridges of fingerprints are formed in skin layers that are not constantly regenerated, so these ridges will eventually reappear.
What are the functions of sebaceous secretions?
Sebaceous secretions, sebum, lubricate and protect the keratin of the hair shaft, lubricate and condition the surrounding skin, and inhibit bacterial growth.
What is the most common skin cancer?
The most common skin cancer is basal cell carcinoma.
Identify two types of exocrine glands found in the skin.
Two types of exocrine glands found in the skin are sebaceous (oil) glands and sweat glands.
What are the capillaries that supply the epidermis located?
The capillaries that supply the epidermis are located in the papillary layer of the dermis, where they follow the contours of the epidermis-dermis boundary.
Describe the location of the dermis.
The dermis, a connective tissue layer, lies immediately deep to the epidermis.
Identify the five layers of the epidermis.
The five layers of the epidermis are the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.
Describe a typical stand of hair.
A typical strand of hair is a keratinous strand produced by epithelial cells of a hair follicle.
What happens when the arrector pili muscle contracts
Contraction of the arrector pili muslce pulls on the hair follicle, making the hair stand errect. The result is sometimes known as "goose bumps."
Dandruff is caused by excessive shedding of cells from the outer layers of skin in the scalp. Thus, dandruff is composed of cells from which epidermal layer?
Dandruff consists of cells of the stratum corneum.
Deodorants are used to mask the effects of secretions from which type of skin gland?
Deodarants are used to mask the odor of apocrine sweat gland secretions, which contain severla kinds of organic compunds that have an odor or produce an odor when metabolized by skin bacteria.
If a burn on the forarm destroys the epidermis and the deep dermis and then heals, will hair grwo again in the affected area>
Even though hair is a structure dervived from the epidermis, the follicles are in the dermis. When the epidermis and deep dermis are destroyed, new hair will not grow.
List the five major functions of the integumentary system.
Five major functions of the integumentary system include protection, temperature maintenance, synthesis and storage of nutrients, sensory reception, and excretion and secretion.
Explain the relationship between sunlight exposure and vitamin D3 synthesis.
In the presence of ultraviolet radiation in sunlight, epidermal cells in the stratum spinosum and stratum basale convert a cholesterol-related steroid into vitamin D3.
Name the two pigments in the epidermis.
The two pigments in the epidermis are carotene, an orange-yellow pigement, and melanin, a brow, yellow-brown, or black pigment.
Why does exposure to sunlight or sunlamps darken skin?
When exposed to the ultraviolet radiation in sunlight or tanning lamps, melanocytes in the epidermis (and dermis) synthesize the pigment melanin, darkening the skin.
Why does the skin of a light-skinned person appear red during exercise in hot weather?
When skin gets warm, arriving oxygenerated blood is diverted to superficial blood vessels to eliminate heat. The oxygenerated blood imparts a reddish coloration to the skin.